1. Technical Field
The present relates to a liquid-jet head and a liquid-jet apparatus that jet a liquid from nozzle orifices, and particularly relates to an inkjet recording head and an inkjet recording apparatus that eject ink as the liquid.
2. Related Art
As a representative example of a liquid-jet head, an inkjet recording head that eject ink droplets as a liquid from nozzle orifices is known, for example. Specifically, such an inkjet recording head is provided with pressure generating chambers communicating with the respective nozzle orifices, and ejects ink droplets from the nozzle orifices by generating pressure change in the pressure generating chambers by use of pressure generators such as piezoelectric actuators.
In addition, such an inkjet recording head is provided with a plurality of pressure generating chambers and a manifold that is provided commonly for the plurality of pressure generating chambers. The manifold and each of the pressure generating chambers are connected by an ink supply path, a communicating path, and the like which generate passage resistance, so that the pressure changes in the pressure generating chambers are directed toward the nozzle orifices.
In this connection, there is a proposed ink supply path that is caused to generate passage resistance by making a depth thereof smaller than that of the pressure generating chamber in a lamination direction of a passage forming substrate and a joint plate, which is another member joined to the passage forming substrate (see for example Japanese Patent No. 3422364).
Alternatively, there is another proposed ink supply path that is caused to generate passage resistance by making a width thereof smaller than that of the pressure generating chamber (in a parallel direction of the pressure generating chambers) (see for example JP-A-2005-53080).
However, if an external pressure is applied to the passage forming substrate, such application of the external pressure may lead to destruction of a compartment wall which defines the ink supply path or the communicating path because the compartment wall has a low rigidity, and may also lead to a problem that destruction such as cracking occurs in a vibration plate due to flexural deformation of the vibration plate, the piezoelectric actuator, or the like. Note that such an external pressure, which is applied to the passage forming substrate, is generated, for example, when a joint plate such as a reservoir forming plate (a manifold forming plate) or a sealing plate is joined to the passage forming substrate, or at the time of handling or attachment in the form of the passage forming substrate or the inkjet recording head, or similar situations.
In particular, to meet an increasing demand for arranging the nozzle orifices at a higher density, the interval of the nozzle orifices in the parallel direction of the pressure generating chambers is shortened, which in turn decreases the rigidity of the compartment walls on both sides of ink supply path and the communicating path in the parallel direction. In addition, the rigidity of the compartment walls is also decreased by a reduction in thickness of the passage forming substrate.
In the case where the width of the ink supply path is made smaller than that of the pressure generating chamber (in the parallel direction) as described in JP-A-2005-53080, although the thickness of the compartment walls defining the ink supply path becomes larger than in the case of Japanese Patent No. 3422364, there is a possibility that destruction due to an external pressure occurs because of the high-density arrangement of the pressure generating chambers (ink supply paths). For this reason, the above-described problem occurs due to the insufficient rigidity of the compartment walls defining the communicating paths regardless of the presence or absence of the ink supply paths.
Moreover, the above-described problems may occur not only in the inkjet recording head but also in a liquid-jet head that jets a liquid other than ink.